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> -----Original Message----- > From: Craig Stoops [mailto:[EMAIL PROTECTED] > Sent: Thursday, September 25, 2003 7:10 PM > To: [EMAIL PROTECTED] > Subject: [t13] Suggested clarifications to SATA Link layer spec > > ... > > Second, I think that some clarification around > ALIGNs and CONTs should be made. The spec notes > (referring to the 1.0a spec) in 7.4.5 para 2, that > ALIGNS are excluded in sentence 2, but doesn't in > sentence 3. This leaves open the interpretations of > whether the following sequences are legal: > 1) PRIM, PRIM, ALIGN, ALIGN, CONT > 2) PRIM, ALIGN, ALIGN, PRIM, CONT > 3) and as seen by the receiver missing one PRIM: PRIM, ALIGN, ALIGN, CONT > > I think both are legal as noted elsewhere the PHY may > be discarding ALIGNs, thus the resulting sequence is > PRIM, PRIM, CONT which is what we want. However someone > else might argue that the whole purpose of requiring > 2 PRIMs before sending a CONT was to be sure that the > PRIM was seen, and that might not hold true if they > are separated by the ALIGNs. I was never quite clear > on why a privitive would not bee seen in the first > place, maybe someone can enlighten me about the > thought behind that statement. If you have an error - bad disparity, corrupted bits, etc. - on either the first or second PRIM (but not both), this rule ensures that the receiver still knows what primitive is being CONTinued. The transmitter has to send two PRIMs before the CONT, but the receiver only cares about one PRIM. <bad> PRIM CONT dword dword ... works fine - the receiver assumes PRIM is being repeated. PRIM <bad> CONT dword dword ... The bad dword is ignored as far as CONT is concerned, so the receiver assumes PRIM is being repeated. PRIM1 PRIM2 CONT dword dword ... The receiver would assume PRIM2 is being repeated. The transmitter is not supposed to send this. > Thanks, > Craig Stoops -- Rob Elliott, [EMAIL PROTECTED] Hewlett-Packard Industry Standard Server Storage Advanced Technology https://ecardfile.com/id/RobElliott
